This invention relates to the treatment of sewage and enrichment of solid fuels, and is related to the subject matter in my prior co-pending application, Ser. No. 703,438, filed July 8, 1976, now abandoned and the subject matter in my prior application, Ser. No. 704,077, filed July 9, 1976, now U.S. Pat. No. 4,028,040.
In my prior related applications aforementioned, the treatment of sewage and various hydrocarbon solids is dealt with in connection with the production of various petrochemical products. In general, steam is mixed with the raw feed under controlled temperature and pressure conditions effecting release of gases and volatiles therefrom, and a solid residue recovered. The prior art of record in the aforementioned prior related applications also discloses apparatus utilized in such processes, including the conveyance of slurries by bottom-mounted augers through horizontally elongated chambers into which steam is injected. Such prior apparatus and processes have been utilized for distilling hydrocarbons from granular materials such as wood or extraction of oil from oil shale and sand. The treatment of solid fuels such as coal and coke is also disclosed, including its hydrogenation and the removal of sulphur compounds therefrom.
The use of such apparatus and methods as aforementioned for enrichment of low energy content, solid fuels by treatment with raw sewage has not been fairly taught until now, and it is therefore an important object of the present invention to provide apparatus of the aforementioned type specifically adapted for the simultaneous treatment of raw sewage and enrichment of solid fuels. The foregoing objective is especially important in view of the present awareness of ecological deterioration caused by untreated sewage and the need for alternative sources of fuel. It is therefore another object of the present invention to provide an economical method of making an enriched fuel from relatively inexpensive and waste materials.